Conventional digital imaging devices or cameras have a lens (which may include multiple lens elements) that focuses image light onto an image sensor that measures the image light and generates an image based on the measurements. FIG. 1 illustrates a common configuration for a digital imaging device 100. FIG. 1 includes an image sensor 101 and optical efficiency lenses 110 disposed over image sensor 101. Optical efficiency lenses 110 function to draw as much light as possible into the pixels for measurement. Optical efficiency lenses 110 may be microlenses disposed over each pixel of image sensor 101. An infrared (“IR”) filter 115 may be disposed over optical efficiency lenses 110 and image sensor 101 to filter out IR light from being measured by image sensor 101. Lens 120 is disposed over image sensor 101 to focus image light 190 onto the pixels of image sensor 101. Lens 120 may include convex and/or concave lens elements 123 that give lens 120 a certain focal length. The focal length of lens 120 may correspond with a Depth of Field. Depth of Field refers to the range of distances in the field of view of an image sensor that appear to be well focused in an image captured by image sensor 101.
It is possible for a separation between lens 120 and image sensor 101 to be adjusted, which may result in different focus distances with different corresponding depths of field. However, digital imaging device 100 only has one depth of field in any given image because lens 120 has one focus distance at one time. For example, the foreground of an image may be in focus because it is within the depth of field for that image, but the background of the image may be blurred because it was not within the depth of field for that image. Therefore, a device or method that allows a digital imaging device to have an extended depth of field would be advantageous.